Damper Cage Research Articles

Wave-resistance analysis of turbo-generator rotors with subtransient asymmetry or symmetry

This paper describes a method by means of which the wave resistance and, approximately, the negative-sequence losses of anisotropic turbo-rotors can be determined from standstill measurements on the test bed and divided into the components for the pole and field winding regions. For turbo-rotors with incomplete damper cage a marked difference can be demonstrated between the specific surface resistances and losses of these two peripheral zones, which may be attributed entirely to the pole iron. When the damper cage is complete, this iron is largely relieved. Thus the pronounced influence of the damper Structure on the rotor wave resistance, as well as on the negative-sequence resistance and losses of solid-rotor synchronous machines is proved direct and confirmed quantitatively.

Starting performance of salient-pole synchronous motors

IN recent years, two papers on the subject of salient-pole synchronous motors have been published in which practical methods for calculating the starting performance are derived on the basis of considerations that take into account all the unsymmetrics of this type of machine; the authors of these two papers are respectively H. V. Putman and T. M. Linville. Application of the Putman method gives at small values of the slip torque values that are somewhat too high; on the other hand, application of the Linville method is rather laborious, especially when the damper cage has a relatively large number of bars per pole. In view hereof, the author presents in this paper another method of calculating the starting performance of a salient-pole synchronous motor, a method which also takes into consideration all the unsymmetrics of this machine. This new method is, on the one hand, much simpler to apply than the Linville method, while on the other hand, it leads to more accurate results than the Putman method. It has been used for many years in the calculation and design of machines of various ratings and speeds, and has always given satisfactory results.

Starting Performance of Salient-Pole Synchronous Motors

IN recent years, two papers on the subject of salient-pole synchronous motors have been published in which practical methods for calculating the starting performance are derived on the basis of considerations that take into account all the unsymmetrics of this type of machine; the authors of these two papers are respectively H. V. Putman and T. M. Linville. Application of the Putman method gives at small values of the slip torque values that are somewhat too high; on the other hand, application of the Linville method is rather laborious, especially when the damper cage has a relatively large number of bars per pole. In view hereof, the author presents in this paper another method of calculating the starting performance of a salient-pole synchronous motor, a method which also takes into consideration all the unsymmetrics of this machine. This new method is, on the one hand, much simpler to apply than the Linville method, while on the other hand, it leads to more accurate results than the Putman method. It has been used for many years in the calculation and design of machines of various ratings and speeds, and has always given satisfactory results.